Extension-tower.



J. V. GRANDINETTI.

EXTENSION TOW ER.

APPLICATION FILED DEC. 4. I915.

L22Q0 Patented Apr. 10, 1917.

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J. V. GRANDINETTI.

EXTENSION TOWER.

APPLICATION FILED DEC. 4. 1915.

Patented Apr. 10, 1917.

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awe/who e half! JOSEPH V. GRANDINETTI, 0F PATCHOGUE, NEW' YORK.

EXTENSION-TOWER.

Specification of Letters Patent.

Patented Apr. it), 1917.

Application filed December 4, 1915. Serial No. 65,046.

To all whom it may concern:

Be it known that I, JOSEPH V. GRANDI- NETTI, a citizen of the United States, residing at Patchogue, inthe county of Sufiolk and State of New York, have invented certain new and useful Improvements in Extensible Towers; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The invention relates to improvements in towers.

The object of the present invention is to improve the construction of towers and to provide an automatic tower designed for use in fire departments and various other purposes and equipped with an extension tower provided at the top with a platform and adapted'to be operated therefrom to raise and lower it the desired height.

A further object of the invention is to provide an automatic tower of this character designed to be mounted on an automobile or other wheeled vehicle and equipped with counter-balancing means for enabling the tower to be easily raised and lowered.

With these and other objects in view the invention consists in the construction and novel combination and arrangement of parts hereinafter fully described, illustrated in the accompanying drawings and pointed out in the claims hereto appended, it being understood that various changes in the form, proportion and minor details of construc tion may be resorted to without departing from the spirit or sacrificing any of the advantages of the invention.

In the drawings Figure 1 is a side elevation partly in section illustrating an automatic tower constructed in accordance with this invention,

Fig. 2 is a vertical sectional view of the same,

Fig. 3 is a horizontal sectional view,

Fig. 4 is a plan view of the top rectangular guide frame, 7

Fig. 5 is a detail perspective view of one of the horizontal approximately L-shaped guides,

Fig. 6 is a detail sectional view taken substantially on the line 66 of Fig. illustrating the construction of the gearing for actuating the diagonally arranged lazytongs, W n

Fig. 7 is a detail sectional view illustrating the manner of mounting the rack bar,

Fig. 8 is a detail view of one of the antifriction devices.

Like numerals of reference designate corresponding parts in the several figures of the drawings. In the accompanying drawings in which is illustrated the preferred embodiment of the invention, the adjustable ladder comprises in its construction a hollow base 1 preferably supported by leveling jacks 2 upon the body or running gear of a wheeled vehicle which may be an automobile or truck to render the automatic ladder portable and enable the same to be readily transferred from one place to another as rapidly as desired.

The leveling jacks which are designed to be arranged in pairs at the front and rear of the base may be of any desired construction and any preferred number may of course be employed and they are intended to level the base when the supporting vehicle is on uneven ground. The base which is preferably hollow to house the gearing for operating the extension tower may be of any other preferred construction and the said extension tower comprises vertically movable side lazy-tongs 3 and a vertical movable diagonally disposed actuating lazy tongs a composed of any desired number of pivotally connected levers or members, the connecting pivots 6 of the side lazy-tongs operating in slots of approximately L-shaped horizontally disposed guides 7. The guides 7 which are arranged at each of the corners of the extension tower are composed of angularly related arms 8 having longitudinal slots 9 in which the said pivots 6 slide. The side lazy-tongs are connected at their lower ends by links 10 with the base and the lower ends of the levers or members of the diagonally disposed actuating lazytongs are connected by suitable pivots 11 to spaced rack bars 12 provided at their inner faces with teeth 13 which mesh with a pinion 14 located between the rack bars as clearly illustrated in Fig. 2 of the drawings. The rack bars are slidable in suitable guides 15 which are provided with ball bearings 16 or other suitable fastening devices for enabling the rack bars to slide with a minimum amount of friction in the operation of the extension tower lift The upper ends 18 of the upper levers or members of the diagonally disposed actuating lazy-tongs operate in a slot or opening 19 of a diagonally arranged guide 20 of a rectangular guide frame 21 which is provided at each of its sides with a guide slot or opening 22 for the reception of t 1e upper ends of the levers or members of the side lazy-tongs. The rectangular guide frame 21 is equipped with suitable anti-friction devices 23 which are preferably in the form of carriages slidable along the guide frame at the sides and at the diagonally arranged portions and consisting of upper and lower rollers or wheels mounted on suitable spindles at the top and bottom of the guide frame and connected by cross bars or mem-- bers 24 carrying a central pivot 25 which receives the upper ends of the lazy-tong levers. By this construction the lazy-tong levers have pivotal action and are adapted to slide inwardly and outwardly 011 the rectangular guide frame. While the rollers or Wheels of the anti-friction devices are shown in the drawings mounted 011 the cross pieces or members 2 1 the supporting frame or members 2 1 may be of any other desired construction as will be readily understood.

The rectangular guide frame carries corner posts 26 which support a platform 27 adapted to support one or more persons.

The platform may be of any desired con,

struction and in practice a railing or similar means may of course be employed to prevent persons from falling off the platform.

The pinion which meshes with the slidable rack bars is mounted on a horizontal shaft 28 disposed diagonally and connected by bevel gears 29 and 30 with a vertical shaft 31 journaled in suitable bearings of the base and carrying a horizontal spur gear 32 which meshes with an intermediate gear 33 mounted on a counter-shaft 3A and meshing with a spur gear or pinion 35 of a vertically disposed operating shaft 36.

The operating shaft 36 is composed of telescopic sections 37 and is equipped at its upper end with suitable operating handles 38 by means of which the vertical operating shaft 36 is rotated. The vertical operating shaft 36 is journaled in suitable bearings and the sections which are preferably of rectangular or other polygonal shape cross sectionally are adapted to slide or telescope on each other as the extension tower is raised and lowered. By the construction shown the extension tower is adapted to be raised and lowered by persons on the plat- Copies of this patent may be obtained for five cents each, by addressin'g the Commissioner of Patents form 27 and if desired suitable guy ropes may be employed for steadying the extension tower. This can be conveniently done by persons on the ground arranged opposite the various sides of the tower. In order to enable the extension tower to be raised and lowered easily it is counter-balanced by weights 39 secured to the outer ends of cables or ropes A0 or other suitable flexible connections which are connected at their inner ends with the slidable rack bars. The flexible connections 40 are arranged on guide pulleys 4:1 and when the rack bars are moved inwardly to elevate the extension tower the weight'desccnds and assists the upward movement of the tower. Also when the extension tower is lowered the weights are raised and assist in counter-balancing the tower as will be readily understood.

WVhat is claimed is 1. A device of the class described including an extension tower having a platform and lazy-tongs supporting the platform and means for operating the lazy-tongs including slidable rack bars, a pinion meshing with the rack bars, means for rotating the pinion and counterbalancing means connected with the rack bars and operated by the sliding movement of the same for counter-balancing the extension tower to assist in raising and lowering the same.

2. A device of the class described including an extension tower having a platform and lazy-tongs supporting the platform and means for operating the lazy-tongs including slidable rack bars, a pinion meshing with the'rack bars, means for rotating the pinion, and means for counter-balancing the extension tower consisting of flexible connections attached to the slidable rack bars, weights secured to the flexible connections and guide pulleys receiving the flexible connections.

3. A device of the class described including an extension tower comprising side lazytongs, a. diagonal actuating lazy-tong, and a rectangular guide frame provided at its sides with guides and having a diagonal guide, said guides receiving certain of the levers or members of the lazy-tongs between the pivots of the same. 7

In testimony whereof I atlix my signature in presence of two witnesses.

JOSEPH v. GRANDINETTI.

Washington, D. G. 

